Fumigation process



Patented July 31, 1951 niline & Film Corporation, New York; N. Y5,

I a corporation ofv Delaware No Drawing.

This invention relates to improved methods for checking the growth of and destroying pests such as bacteria, insects and mice and more particularly to methods for fumigation. In the milling industries, for example, millions of dollars are lost annually due to the damage to the grain or flour by the presence of insects and other pests. Perhaps the more common method of combating insects in mills is by means of fumigation with methyl bromide, which is of course an extremely dan erous fumigant to handle, particularly since it does not have such a strong odor as to warn the layman of its presence.

It is therefore an object of the present invention to provide an improved process of fumigaion.

It is a further object of the present invention to provide an improved process for fumigating grain without injuring the grain.

It is a further object of the present invention to provide an improved process of fumigation, utilizing a compound which has a noticeable odor, thus warning people of its presence.

These and other objects of the present invention are attained by the improved process which comprises evaporating in the air surrounding the pests a compound having the following general formula:

The following example illustrates the results of tests on certain of these compounds on the most destructive of the insects commonly found in flour mills which is the confused flour beetle.

EXAMPLE Thirty-three mg. of bis(2-chloroethy1) acetal of acetaldehyde was pipetted into a 22-1iter round Application Novembe 19,1948, Serial No. 61,139

claims. (01.16742) 5 bottom flask, and the flask was closed with a rubber stopper, from which was suspended a small wire-screen cage containing 50 confused flour beetles (trz'bolium confuswm). The beetles were exposed to the vapors of the compound for 5 hours at about 25 C., after which time they were withdrawn from the flask, transferred to clean beakers, and supplied with a small amount of whole wheat flour as food. A mortality of 96% was observed in seven days.

By varying the concentration of compounds tested according to the above procedure, dosagemortality curves were plotted, and from them the following data were obtained:

It will be seen from the above table that the fumigants compare very favorably with the last two standard fumigants.

These acetals may be used to kill insects other than the confused fiour beetles, such as the other insects commonly found in flour mills, grain elevators, etc., as well as household insects, insects attacking storing products, insects infesting clothing, upholstered furniture, furs, carpets, insects in warehouses, etc. In addition, mites and rodents such as mice are killed by the fumigant and growth of fungi and bacteria is inhibited thereby. The fumigant is generally effective in any location where vapors of the compounds may be confined for a definite period of time.

The acetals may also be used in combination with other insecticides and fumig-ants, such as dichloroethyl ether, methyl bromide, carbon disulfide, ethylene oxide, ethylene dichloride, and the like.

Furthermore, they may be applied by spraying into the confining area, with or without such volatile solvents as carbon tetrachloride and the like; and may be used as aerosols in conjunction with compounds which are gaseous at ordinary temperatures and atmospheric pressure, such as Freon-11 and Freon-12. One method which may be used to form the fumigant is passing air over a heated vessel of the compounds.

formaldehyde bis (2-chloro-ethyl)acetal and acetaldehyde bis(2-ch10r0-ethyl) acetal.

2. A process for destroying insects comprisin evaporating formaldehyde bis (2-chloroethyl) acetal in the air surrounding the insects.

3. A process for destroying insects comprising evaporating acetaldehyd bis (2-chloroethyl) 15 acetal in the air surrounding the insects.

EMILY M. OWEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name v Date 2,129,025 Rieche et al.' Sept. 6, 1938 FOREIGN PATENTS Number Country Date 711,290 France Sept. 7, 1931 OTHER REFERENCES I Roark et al., U. S. D. A. Tech. Bull. N0. 162 entitled, Tests of Various Aliphatic Compounds as Fumigants, March 1929, page 18.

Beilstein, Handbuch der Organischen Chemie,

band 1, page 575 (1918). (Copy in P. O. Lib.) 

1. A PROCESS FOR DESTROYLING PESTS COMPRISING EVAPORATING IN THE AIR SURROUNDING THE PESTS A COMPOUND SELECTED FROM THE GROUP CONSISTING OF FORMALDEHYDE BIS (2-CHLORO-ETHYL) ACETAL AND ACETALDEHYDE BIS(2-CHLORO-ETHYL) ACETAL. 